Soya-bean inhibitor

FURUSE M, YANG s I, MURAMATSU T, OKUMURA J (1990) Enhanced release of cholecystokinin by soya-bean trypsin inhibitor in chickens. Scand J Gastroenterol. 25 1242-6. 

Sodium Azide is often used (at 0.01% concentration) as an anti-bacterial preservative. The same concentration should be present in an all the buffers against which the sample is dialyzed (see below). Soya Bean trypsin inhibitor is often added to protein samples at 10 pg/ml, but not usually to dialysis buffers. 

Pr4 trypsin-like cysteine 26.7 4.6 iodoacetic acid, N-ethylmaleimide, pCMB, DTNB, DEPC, TLCK, protein inhibitors from soya bean and chicken ovoinhibitor Cole et al. (1993)... 

The concept of a proteolytic mechanism in the production of inflammatory manifestations is supported by the demonstration of anti-inflammatory activity in various protease inhibitors, e.g. the trypsin inhibitors of the pancreas, soya bean, ovomucoid and potato . It is interesting to note that the inhibitor from potatoes exerts its effect even after the inflammation is well established , suggesting that protease action is a continuing feature of inflammation and not simply an initiating process. Various esterase inhibitors (dyflos, quinine, quinidine and chloroquine) also reduce capillary permeability induced by heat and the permeability globulins . 

Cima LG, Vacanti JP, Vacanti C, Ingber D, Mooney D, Langer R (1991) Tissue engineering by cell transplantation using degradable polymer substrates. J Biomech Eng 113 143-151 Clarke E, Wiseman J (2005) Effects of variability in trypsin inhibitor content of soya bean meals on true and apparent ileal digestibility of amino acids and pancreas size in broiler chicks. Anim Feed Sci Technol 121 125-138... 

For many plants, methyl jasmonate is a key elicitor, which initiates a series of response mechanisms to herbivores, like the synthesis of protease inhibitors and the increased formation of secondary metabolites (cf section 3.3- Jasmonoids). The effects were already well-known for tomato and tobacco plants, but also for Catharanthus and Cinchona seedlings and for soya beans. In the case of yew cells, this additive enabled to increase the paclitaxel production from 3 to 117 mg, and later to 295 mg per litre of fermentation broth. 

Friedman, M., Grosjean, O.K. and Zahnley, J.C. (1982a). Inactivation soya bean trypsin inhibitors by thiols. J. Sci. Food Agric.. 165-172. 

Inactivation of soya bean trypsin inhibitors by thiols. 

The nutritional value of a protein also depends on its digestibility here again, plant proteins tend to be inferior to animal proteins. Their poor digestibility results from (1) the presence of peptide bonds which are relatively resistant to the digestive enzymes, (2) the presence of enzyme inhibitors such as the trypsin inhibitor present in soya beans (page 177), and (3) the presence of fibre which hinders the access of proteolytic enzymes (page 130). 

A problem with the pulses is the presence of various types of toxin, some of which are only destroyed by prolonged heat. For example, soya beans contain a trypsin inhibitor. Aflatoxins produced by the mould Aspergillus flavus, which may contaminate groundnuts, have been found to damage the liver and cause carcinoma in various species. These substances have restricted the use of groundnuts both for human and animal nutrition. Lathyrism (page 419), which may produce permanent paralysis, results from the consumption of large quantities of the pea. Lathyrus sativus, usually when the main crops have failed. 

Immobilization of soya bean trypsin inhibitor (STI) on Toyopearl AF Tresyl 650M... 

Trypsin inhibitors are not the only antinutritive factors in soya beans that may slow the growth of farm animals. For example, the slowdown of animal growth, for which trypsin inhibitors are responsible, is about 40% of the total antinutritive activity of raw soya beans. About 25% of the antinutritive activity can be attributed to lectins and the rest to other antinutritional substances. 

Non-toxic lectins are lectins of garlic, onions, leeks, tomatoes and amaranth. Of the common lectins, those of peanuts, lentils, peas, common beans and soya beans are slightly toxic, wheat lectins are moderately toxic, and lectins of some beans (such as Jack beans) are highly toxic, while castor seed lectins are lethal (Table 10.21). Some lectins (such as lectins of garlic) have prebiotic effects and inhibit undesirable intestinal microflora Escherichia coli). Often, lectins are not the only toxic substances of the plant material. For example, lectins of soybean seeds participate in their antinutritional and toxic effects at a level of about 25%, but trypsin inhibitors are about 40% and the rest is covered by saponins and other substances. 

The plasma or serum of mammals is able to inhibit all kallikreins. This inhibition appears to be reversible. The acidification of an inactive mixture of kallikrein and plasma results in the reappearance of kininogenase activity. In addition, diiso-propylphosphorofluoridate (DFP), soya-bean trypsin inhibitor, potato trypsin inhibitor, some ester substrates of kallikrein and other substances have been shown to decrease the activity of one or several kininogenases. 

Fluorocitrate. Fluoroacetate is toxic because it is converted in vivo to the (2R, 3R) stereoisomer of 2-fluorocitrate which is a potent inhibitor of citrate transport across the mitochondrial membrane (7) and is also an inhibitor of the citric acid cycle enzyme, aconitase (8,9). Accumulation of 2-fluorocitrate induces convulsions and ultimately heart failure and death. It is interesting that certain plants such as alfalfa Medicago sativa ssp sativa) (10) soya bean Glycine max) (11) and tea Thea sinensis) (12) can accumulate low levels of 2-fluorocitrate when grown in the presence of fluoride suggesting that a wide range of plants possess the ability to biosynthesise fluoroacetate and convert it to 2-fluorocitrate in small quantities. 

Chloroplasts were isolated from 14-day-old peas by grinding leaf tissue in the medium of Stokes and Walker (1971), and resuspended in the medium of Renger et at. (1976) Incubations with trypsin or chymotrypsin (Sigma types XIII, TCPK VII TLCK respectively) were at pH 7.2, temp. 23 C and were stopped by addition of Soya Bean trypsin inhibitor (Sigma). 

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